1. Field of the Invention
The present invention relates to an antenna-embedded laminated glass with an antenna element sealed between glass sheets.
2. Description of the Related Art
Heretofore, an antenna sheet, which includes a conductive strip for an antenna element and an adhesive layer disposed on a base sheet as disclosed in e.g. JP-A-2001-119219, has been known. This antenna sheet can function as a glass antenna by being bonded to a surface of a glass sheet through the adhesive layer.
Such an antenna sheet is affixed to a surface of a glass sheet in use. From this viewpoint, when such an antenna sheet is bonded to, e.g., an interior surface of the front windshield of a vehicle, the conductive strip needs to be covered with a transparent protective layer. The protective layer is disposed for the purpose of preventing the conductive strip from being damaged and being disconnected by an external force. In some cases, a boundary line between the protective layer and the glass sheet with the antenna sheet affixed thereto is visible since the protective layer has a different refractive index from the glass sheet, and the protective layer covers the glass sheet over a relatively wide area. For these reasons, such an antenna sheet has a problem of poor appearance and a problem of obstructing a driver's view.
On the other hand, in an antenna-embedded laminated glass with an antenna element sealed between glass sheets as disclosed in e.g. JP-A-2-82701, an antenna element is protected by the glass sheets. Even when such an antenna-embedded laminated glass is applied to an automobile windshield, there is no problem, such as a poor appearance caused by the provision of a protective layer in a region except for the provision of the antenna element.
Such an antenna-embedded laminated glass is classified into a print type wherein conductive paste is printed in a desired pattern on an inner surface (mating surface) of a glass sheet to form an antenna element, and an intermediate film embedded type wherein an antenna wire is embedded in an intermediate film (typically made of polyvinyl butyral) interposed between glass sheets.